High band degeneracy contributes to high thermoelectric performance in p-type Half-Heusler compounds

Chenguang Fu, Tiejun Zhu*, Yanzhong Pei, Hanhui Xie, Heng Wang, G. Jeffrey Snyder, Yong Liu, Yintu Liu, Xinbing Zhao

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

176 Scopus citations

Abstract

Half-Heusler (HH) compounds are important high temperature thermoelectric (TE) materials and have attracted considerable attention in the recent years. High figure of merit zT values of 0.8 to 1.0 have been obtained in n-type ZrNiSn-based HH compounds. However, developing high performance p-type HH compounds are still a big challenge. Here, it is shown that a new p-type HH alloy with a high band degeneracy of 8, Ti-doped FeV0.6Nb0.4Sb, can achieve a high zT of 0.8, which is one of the highest reported values in the p-type HH compounds. Although the band effective mass of this system is found to be high, which may lead to a low mobility, its low deformation potential and low alloy scattering potential both contribute to a reasonably high mobility. The enhanced phonon scattering by alloying leads to a reduced lattice thermal conductivity. The achieved high zT demonstrates that the p-type Ti doped FeV0.6Nb0.4Sb HH alloys are promising as TE materials and offer an excellent TE performance match with n-type ones for high temperature power generation.

Original languageEnglish (US)
Article number1400600
JournalAdvanced Energy Materials
Volume4
Issue number18
DOIs
StatePublished - Dec 1 2014

Keywords

  • Half-Heusler alloys
  • Semiconductors
  • Thermoelectric materials

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

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